Hermann muller



UNITED STATES aTnNT FFICE.,

HERMANN MLLER, OF NUREMBERG, GERBIANY.

HlGll-TENSlGN SWiTCH..

SPECIFICATION forming part ofl Letters Eatent No. 595,887, datedDecember 21, 1897.

Application fled June 2, 1897. Serial llo. 643,216. (No model-l To allwhom zit may concern:

Be it known that I, HERMANN MLLER, a citizen of the Empire of Germany,residing in Nuremberg, in the Kingdom of Bavaria, in the Empire ofGermany, have invented certain new and useful Improvements inHigh-Tension Switches, of which the following is a specification. n

This invention relates to certain improvements in high-tension switchesin which the oxidation of the contacting parts and the consequentobjectionable insulation of these parts can be to a great extentprevented and neutralized and a high-tension switch of superiorproperties and durability is obtained.

It has been found in lightning-protectors that the passage of a spark ofa high-tension current can be readily prevented when two conditions arepresent, as follows: First,when the contacting parts by which thecircuit is closed are formed of an easily-oXidiZin g metal and the oXidof which is a good non-conductor of electricitythat is to say, composedof a non-arcing metal; second, when the distance between the contactingparts is very small, as when the distances between the contacting partsare large, in consequence of the greater heating and the consequentevaporation of the metal, an arc may be formed as described by Wurts inhis papers. lt was therefore proposed to form the contacting parts ofballs or rollers arranged in a row, so that when these balls or rollersare pressed together the circuit is closed, while the circuit isinterrupted by separating the balls or rollers or the formation of smallspaces between the contacting parts when the pressure on the parts isremoved. The small sparks which are formed on the separation of thecontacting` parts are, in consequence of the oXid, quickly extinguished,as before described. The insulating` property of the resulting oXid,however, has the disadvantage that after a comparatively short use ofsuch a switch the circuit cannot be entirely and reliably closed.

The object of my invention, therefore, is to obviate these objectionsand provide a switch for high-tension currents, in. which theobjectionable interference of the oxidation of the contacting parts isavoided; and the invention consists of a high-tension switch composed ofaserics of roller-shaped contactpieces arranged in a row, which are madeof easily-oxidizing non-arcing metal and of a mechanism by which saidrollers can be either pressed together or separated from each other insuch a manner that by the closing and opening, respectively, of thecircuit aturnin g motion is imparted to said contact-pieces, as will befully described hereinafter, and finally pointed out in the claims.

ln the accompanying drawings, Figure l represents a front elevation, andFig. 2 is a side elevation, of my improved switch for high-tensioncurrents.

Similar letters of reference indicate corresponding parts.

Referring to the drawings, A represents a plate of non-conductingmaterial on which a series of contact-pieces formed in the shape ofrollers a are arranged in line with each other. The roller-shapedcontact-pieces a are made to turn easily on their axes, which aremounted on flat springs b. The contactrollers o are divided into twogroups, an upper and lower, and between said groups eccentric cams darea1ranged,wl1ich are mounted on a shaft d', that is turned by ahand-lever d2. The eccentric cams d are in contact with the adjacentrollers of each group and produce the pressing;` together of thecontactrollers of each group when the hand-lever die is moved in thedirection of the arrows into position for closing the circuit. Then thehand-lever is returned into its normal position, the eccentric camsrelease the rollers and produce the interruption of the contact of thesame. The contact-rollers a at the end of each group are mounted onheavy metallic plates e, so that they can change their position butlittle, even when the intermediate rollers are forced in contact witheach other.

lt is obvious from a cursory examination of the construction describedthat during the closing as well as during the opening of the circuit aturning motion is imparted to all the contact-rollers a up to CLG. As,furthermore,

the friction of the different contact-rollers on their shafts differsslightly it follows that after each use of the switch new contactportions of the cylindrical surface of the rollers are placed adjacentto each other, so that thereby a greater durability and usefulness Lalof the switch is obtained. Another advantage is that by the friction ofthe rollers any oXid that is formed on the same is removed by thefriction of the rollers With each other. Owing to these two facts theswitch can be used for a much greater length of time without requiringrepairs, which is of considerable importance in high-tension switches,owing to the danger connected with the touching of their parts.

The liereinbefore-described disposition of the rollers can also be usedfor commutators. V'Vith electric currents of great strength it ispreferable to arrange the switch in a shuntcircuit of an ordinarycut-out, so that a connection With comparatively small resistance forthe passage of the current is obtained.

Having thus described my invention, I claim as new and desire to secureby Letters Patent-'- l. A switch for high-'tension currents, consistingof groups of contact rollers made from easily-oxidizable non-arcingmetal, said groups of rollers being mounted on springarms, each rollerbeing normally out of contact with the others, and means for forcing therollers into Contact with each other, While simultaneously a turningmotion is imparted to the same, substantially as set forth.

2. A switch for high tension currents, formed of a group ofcontact-rollers made of easily-oxidizable non-arcing metal, said rollersbeing mounted on spring-arms and normally out of contact with eachother, intermediate ecccntric cams operated by a handlever and adaptedto place the contact-rollers of each group in contact With each other,substantially as set forth.

In testimony that l claim the foregoing as my invention l have signed myname in presence of two .subscribing witnesses.

HERMANN M'ULLniii.

Witnesses:

FRANZ B. W. KING, OSCAR BooK.

